Esters of phosphorus and method of preparation thereof



United States Patent 3,511,857 ESTERS 0F PHOSPHORUS AND METHOD OFPREPARATION THEREOF Charles F. Baranauckas and Irving Gordon, NiagaraFalls, N.Y., assignors to Hooker Chemical Corporation, Niagara Falls,N.Y., a corporation of New York No Drawing. Filed Nov. 12, 1963, Ser.No. 323,114 Int. Cl. C07d 105/04; C07f 9/38 US. Cl. 260347.8 11 ClaimsThis invention relates to novel organic phosphorus compounds. Moreparticularly, it relates to novel esters of phosphonic acid that containfrom two to about 32 hydroxyl groups, the 1,3,2-dioxaphosphorinane ring,to the processes for their preparation, and the novel esters ofphosphorous acid utilized in the preparation of said esters ofphosphonic acid.

In accordance with the present invention the novel esters of phosphonicacid have the structural formula wherein M is the residue of a polyolwherein two hydroxyls are removed from a group of carbon atoms withhydroxyls attached thereto and one carbon atom between the two carbonatoms from which the hydroxyl groups have been removed, A is selectedfrom the group consisting of an aliphatic and an aromatic radical, n isselected from 0 to and the molecule contains from 2 to about 32 hydroxylgroups.

The esters of phosphonic acid of the present invention may also becharacterized as having from two to about thirty-two hydroxyl groups andat least one 1,3,2-dioxaphosphorinane ring with a structural formula ofwherein R is selected from the group consisting of hydrogen, alkyl,alkyl substituted aryl, aryl substituted alkyl, nitro, chloromethyl,brornomethyl, iodomethyl, halogen substituted aryl, hydroxyalkyl, aryl,alkoxyalkyl, hydroxyalkoxyalkyl, alkene, alkyl substituted alkene,halogen substituted alkene, and mixtures thereof, Z is selected from thegroup consisting of alkyl, alkylene, alkene, aryl substituted alkyl,aryl, alkyl substituted aryl, halogen substituted aryl, heterocyclic,hydroxyl substituted alkyl, hydroxyl substituted alkylene, halogensubstituted alkylene, hydroxyl substituted aryl, hydroxyaryl substitutedalkyl, hydroxyalkyl substituted aryl, hydroxyalkyl substitutedheterocyclic and mixtures thereof, and n is from O to 5.

The novel esters of phosphonic acid containing the1,3,2-dioxaphosphorinane ring and from two to about thirty-two freehydroxyl groups are particularly useful phosphorus containing chemicalsand undergo many reactions with other polyfunctional intermediates. Theyreact with polyisocyanates, e.g., toluene diisocyanate or polymethylenepolyphenyl isocyanate to form foamed polyurethanes which are flameresistant and have improved heat distortion temperatures. In addition,the free hydroxyl groups in the 1,3,2-dioxaphosphorinane ringcontainingphosphonates may be reacted with polybasic acids and anhydrides, e.g.,isophthalic acid, fumaric acid, maleic anhydride, to form resinouspolyester compositions that are flame resistant. The novel esters ofphosphonic acids containing the 1,3,2-dioxaphosphorinane ring structuralunit are resistant to hydrolytic attack significantly more than arephosphonates not containing the 1,3,2- dioxaphosphorinane ringstructural unit. The novel esters of phosphonic acid of this inventionare useful for reaction into alkyd resins that may be used to makefilm-forming products with improved resistance to burning. The novelesters of phosphonic acid containing the 1,3,2-dioxaphosphorinane ringstructure and from two to thirty-two hydroxyl groups are particularlyuseful in polyolefins, e.g., polypropylene and polyethylene, to improvethe dyeing characteristics of fibers produced, and these novel estersare not subject to loss by evaporation, hydrolysis or leaching.

The present novel esters may be prepared from a variety of knownstarting materials and through a variety of chemical transformations. Inmany instances the novel esters of the phosphonic acid are prepared fromnovel esters of phosphorous acid. In the instant invention these novelesters of phosphorous acid may be illustrated by the two generalstructural formulae:

OCRz Rz(OH) where R is selected from the group consisting of alkyl,alkenyl and mixtures thereof, and R" is selected from the groupconsisting of hydrogen, alkyl, alkenyl, nitro, halomethyl, arylsubstituted alkyl, alkoxyalkyl, and mixtures thereof and, the sum of xand y is from two to about twelve and wherein R" is as defined above andw is from two to eight. The novel esters of phosphorous acid disclosedin the description, in addition to being utilized as chemicalintermediates, may be used as heat and light stabilizers for halogencontaining vinyl and vinylidene resins. They also are useful asantioxidants, e.g., in natural rubber, synthetic rubber and so forth.

In accordance with this invention it has been found that novel esters ofphosphonic acid having from two to about thirty-two hydroxy groups andcontaining at least one 1,3,2-di0xaphosph0rinane ring may be prepared byreacting a phosphite having the structure of (2) or (3) (ring orbicyclic phosphite) with an organic halide having the general formula ZXwhere Z is defined as above, X is a halogen selected from the groupconsisting of iodine, chlorine, and bromine and m is from one to about5.

In instances where the novel bicyclic phosphites of Formula 3 are used,a stoichiometric or approximately stoichiometric amount of the ZXreactant is employed to open one of the rings in the bicyclic phosphiteto form the 1,3,2-di0xaphosphorinane ring. The Z becomes at- 3 tacheddirectly to the phosphorus atom of the starting bicyclic phosphite,e.g.,

In instances where the novel cyclic phosphites as defined in (2) areused, an Arbuzov-type rearrangement of the phosphite to the phosphonatemay be effected, using catalytic amounts of ZX or heating, when the Rgrouping in the phosphite is the same as Z in the ZX In instances wherethe R grouping in the phosphite is not the same as Z in the ZX it isdesirable to use at least stoic'hiometric quantities of the Z'X reagent.

The selection of the Arbuzov reagent to be used is determined by manyfactors, e.g., the structure of the phosphite that is to be reactedwith, the availability of the number of equivalents of halogen in theArbuzov reagent and so forth. It is preferred to utilize from 0.001 toabout moles of ZX per mole of phosphite. However, better results areobtained when from 1 to about 5 moles of ZX per mole of phosphite areutilized, with' most favorable results being obtained when from 1 to 2moles of ZX per mole of phosphite are employed.

The cyclic phosphites of Formula 2 may be prepared by reacting atriorganic phosphite containing at least one aryl radical with a polyolhaving from 4 to about 14 hydroxyls, in a 1:1 molar ratio in thepresence of a basic catalyst, while the bicyclic phosphite of Formula 3may be prepared by reacting a polyol having from 4 to about 12hydroxyls, with a triaryl phosphite in a 1:1 ratio in the presence of abasic catalyst. A trialkyl phosphite may also be utilized in preparingthe cyclic phosphite of Formula 2, but if such a react-ant is utilizedthe cyclic phosphite is mixed with a quantity of the bicyclic phosphite.

Although a 1:1 molar ratio of phosphite to polyol is preferred, thisratio may be varied and a ratio of 1 to 2 may be employed. When thisratio of polyol is employed phosphites having the formula is formed,wherein B is the residue of the polyol with one hydroxyl removed and Mis the residue of the polyol wherein two hydroxyls are removed from agroup of carbon atoms with hydroxyls attached thereto and one carbonatom between two carbon atoms from which the hydroxyl groups have beenremoved, and the sum of (a) is selected from 2 to 32. Some phosphiteswhich illustrate this feature of the invention are which are thereaction products of triphenyl phosphite and an excess of 2hydroxymethyl butanetriol-l,2,3

4 and triphenyl phosphite with an excess of2-nitro-2hydroxy-methyl-hexandediol-1,3, respectively.

Examples of other phosphites which may be utilized to form the novelphosphite are di-aryl monoalkyls and monoaryl dialkyls such as dicresylbutyl phospite, di-(2,4- xylenyl) butyl phosphite, dicresyl hexylphosphite, dicresyl stearyl phosphite, diphenyl butyl phosphite,diphenyl stearyl phosphite, dibu-tyl-2,4-xylenyl phosphite, dibutylphenyl phosphite, distearyl phenyl phosphite, distearyl cresylphosphite, and so forth. The reaction in preparing the phosphonate fromthe phosphite of Formula 2 is preferably conducted in situ. Theby-product phenol and/or alcohol formed during the reaction is separatedfrom the reaction product on completion of the reaction or during thereaction as it progresses. The reaction is deemed completed when anegative iodine titer is obtained for phosphite in the reaction vessel.

The preferred polyols in this invention have been found to contain1,3-hydroxyls, however appropriate polyols having one carbon atombetween two carbon atoms having hydroxyl attached thereto may also beutilized. It is to be understood that polyols having two or morehydroxyls may be utilized in the practice of this invention to preparethe cyclic and bicyclic phosphites. Polyols having a formula R"C(CH OH)wherein R" is as above defined may also be utilized. Included within thescope of the invention are polyols having hydroxyls on carbon atomsseparated by one carbon atom such as the following:

and other trimethylolalkanes, e.g., trimethylol ethane, trimethylolbutane, trimethylol octadecane and trimethylol decane. Although polyolscontaining from 3 to about 14 hydroxyls may be employed in the practiceof this invention, polyols having from 3 -to 12 hydroxyls are preferred,with polyols containing from 3 to 8 hydroxyls being most favored.

With respect to the novel phosphonates of this inventron of formulatypical specific individual radicals that are illustrative but notlimiting for R and Z are as follows:

5 Alkyl Halo substituted aryl 01 F I I m- I t Hal Hall Hal is selectedfrom Cl, Br, I, and F; and t is an integer from 1 to four,

Hal is selected from Cl, Br, I, and F; and t is an integer from 1 tofour,

Hal,

Hal is selected from Cl, Br, I, and F; and the sum of g is an integerfrom 1 to seven, Alkyl-substituted aryl I CH; I CH l CH CH2 lCHa CHz-CH;

@om 01198011, @jcm-cm C 3 C fi Br- F \/Ol $1 HzCH; F

wherein R" is as defined above.

Among other phosphites that may be utilized as starting reactants in thepractice of this invention are tris 2-methylphenyl) phosphite,

tris 3-methylpheny1) pho sphite,

tris (4-methylphenyl phosphite,

tris (2-chlorophenyl) phosphite,

tris 3-chlorophenyl phosphite,

tris (4-chlorophenyl) phosphite,

tris 2,3-dichlorophenyl phosphite, tris 2,4-dichlorophenyl phosphite,tris 2,5 -dichlorophenyl) phosphite, tris (2,6-dichlorophenyl)phosphite, tris 3 ,4-dichlorophenyl phosphite, tris 3-5-dichlorophenyl)phosphite, tris 2-bromop'henyl) phosphite,

tris 3 -bromophenyl) phosphite,

tris 4-bromophenyl) phosphite,

tris 4-iodophenyl phosphite,

tris (Z-fluorophenyl phosphite,

tris (2-chloro-4-bromophenyl) phosphite, tris 3,5 -dimethylpheny1)phosphite, tris (Z-ethylphenyl) phosphite,

tris (4-ethylphenyl phosphite,

tris 2-cyclohexylphenyl) phosphite, tris (4-octylphenyl phosphite;

tris 3-isobutylphenyl) phosphite,

tris (4-dodecylphenyl phosphite,

tris Z-amylphenyl) phosphite,

tris (4-buty1phenyl phosphite,

tris (Z-tertiary butylphenyl) phosphite, tris(2-secondarybutylphenyl)phosphite, tris (2-nitrophenyl phosphite,

tris 3-nitrophenyl phosphite,

tris 4-nitrophenyl phosphite,

tris (2-methoxyphenyl) phosphite, triphenylphenyl p'hosphite,

tris alpha-naphthyl phosphite,

tris (beta-naphthyl) phosphite, and tris-1-(2,4-dibromo) naphthylphosphite.

Most of these substituted triphenyl phosphites are old compounds. Thosewhich are new can be formed in conventional fashion by refluxing theappropriate substituted phenol in excess with phosphorus trichloride,e.g., as shown in Kosolapoff, Organophosphorus Compounds (1950), page183, and Mayle US. Pat. No. 2,220,845. Generally, triorganophosphitesboth aliphatic and aromatic having from 1 to 70 carbon atoms may beemployed in the practice of this invention with the preferred organicphosphites containing from 1 to 22 carbon atoms, with the more preferredtriorgano phosphites contain n from 1 to 18 carbon atoms.

Arbuzov reagents which may be utilized in the practice of this inventionare alkyl halides, alkylene halides, alkyl substituted alkylenes,cycloalkyl halides, aralkyl halides, and containing between about 1 and70 carbon atoms with the preferred reagents having between 1-22 carbonatoms, with the most preferred having between about 1-18 carbons atoms.Examples of these reagents are, methyl iodide, butyl chloride, butyliodide, pentyl fluoride, pentyl bromide, hexyl chloride, nonyl chloride,nonyl bromide, octyl iodide, octyl bromide, decyl bromide, isodecylbromide, undecyl chloride, undecyl iodide, undecyl fluoride, hexadecylbromide, hexadecyl chloride, stearyl chloride, 1,2-dibromoethane,1,3-dichloropropane, 1,2-dibromo ethyl ether,1,4-dichloro-2-ethoxybutane, alkyl chloride, methalkyl chloride,chloropropylene, chlorobutylene, bromopropylene, iodopropylene,fluorododecylene, dichlorobutylene, dichloropropylene,chlorobromoiodobutene, chloromethylacetylene, bromomethylacetylene,dichlorododecylene, dibromo octadecylene, bromobutene,chlorobromopentene, dichlorobutane, dibromobutane, dibromo decane,difluoro eicosane, methylene iodide, ethylidene bromide, ethylenechlorobromide, propylidene iodide, oxatane dibromide, 1,2-propylenechloride, trimethylene chloride, amylene dibromide, 3,3- bisiodomethyloxatane, 1,4-chloromethyl benzene, carbon tetrachloride,dichlorodibromomethane, acetylene tetra- -bromide, trichloroethylene,fluorochlorobromomethane, methyl chloroform, hexachloroethane;heptachloropropane, perbromoethylene, isomers of the above compounds,and so forth. A cycloalkyl halide as set forth above may be alsoutilized in the invention to form novel esters of phosphonic acid.Examples of these are chlorocyclopropane, dibromocyclopropane,dichlorocyclopropane, bromocyclobutane, bromocyclopentene,2-chloroethyl, bromocyclooctane, chlorocycloheptane,2-chlorocyclopentene, 2 iodo 1,3 cyclohexadiene, 7,7-dichloronorcarene,7,7-dibromonorcarene, 1-chloro-1,3-dimethylcyclohexane,bromocyclopentane, bromodecalin, chlorodecalin, bromocyclotetradecane,chlorocyclopentadecane, 1,2-dibromocyclohexane, l-iodo 1methylcyclopentane, and so forth. It is preferred to utilize cycloalkylscontaining between about 3 to 70 carbon atoms. With cycloalkylscontaining about 3 to 13 carbon atoms being preferred and the mostpreferred cycloalkyls containing between about 3 to 7 carbon atoms.Examples of aralkyl halides and dihalides that may be utilized as anArbuzov reagent in the practice of this invention arediphenylbromomethane, triphenylbromomethane, benzyl chloride, benzalchloride, benzotrichloride, chloromethylnaphthalene, 1-phenyl-l-chloroethane, bromomethylnaphthalene, chloromethylanthracene,bromomethylanthracene, l-phenyl-Z- chloroethane, benzyl bromide,1-phenyl-2-bromoethane, 1phenyl-2-chloropropane,bis-chloromethylnaphthalene, chloromethylpolystyrene,bromomethyltoluene, bromomethylxylene, dichiorobromomethylbenzene,chloromethylanisole, bisbromomethylanisole, bromomethylfluorine, and soforth. It is preferred to utilize an aralkyl containing between about 6and 70 carbon atoms. It is preferred to utilize an aralkyl hydrocarbonhaving between about 6 and 12 carbon atoms, with the most preferredaralkyl hydrocarbons containing between about 6 and 10 carbon atoms. Theease of reaction varies with the nature of the halogen atom in the alkylhalide. The decreasing order of activity is alkyl iodine, alkyl bromide,alkyl chloride, alkyl fluoride.

The above Arbuzov reagents are merely illustrative and not to beconsidered as limiting the invention disclosed herein. It will be clearto those skilled in the art that the Arbuzov reaction or catalyticisomerization may also be effected by compounds selected from the groupconsisting of acyl halides, heteroalkyl halides, alpha-haloketones,alpha-haloamides, alpha-halonitrite, chlorocarbamates, beta-haloesters,epichlorohydrin, epibrimohydrin, and so forth.

Examples of other catalysts which may be utilized to cause an Arbuzovrearrangement are alkali metal halides, such as sodium iodide, potassiumfluoride, sodium bromide, lithium iodide, cesium iodide, and so forth.Isomerization (Arbuzov rearrangement) may also be induced by variousother reagents such as methyl sulfate, cuprous chloride, cuprous iodide,iodine or even by thermal means alone.

The products formed by following the teachings of this invention may bepolymers wherein the polymer contains between 2 and 5 phosphorus atoms.

Products within the scope of this invention are pentaerythritol methylphosphonate; dipentaerythritol methyl phosphonate; tripentaerythritolmethyl phosphonate; pentaerythritol ethyl phosphonate; dipentaerythritolethyl phosphonate; tripentaerythritol ethyl phosphonate;pentaerythritol-, dipentaerythritol-, and tripentaerythritol propanephosphonate; pentaerythritol-, dipentaerythritoland s O--CH2 CHaOH lBrCH (3112B: POCH2-CCHzCHzCHz-CCH2OH :I

O--CHz HzOH BrCH --CHrBr CHzBt/CHzO (III) (d/OCEz /CH2B|.'

/PCH2 S CHzP /C\ (HO CHz) C(CH2)3 CHzO OCHz (CH2)aC(CH2OH) CH\2Br CHzO(i) O OCHz CHzBr P|CH: oH2i o (HOCH C(C 2), CHzO 00111 (CH2)aC(CHzOH)product desired triaryl phosphite may be converted to (11) CHzCl diarylalkyl phosphite by reacting the triaryl phosphite E /CH2OH with a molarproportion of an alcohol. For example, tri- Alk l-O-P C phenyl phosphitemay be reacted with butanol in the pres- \cHzoH O1 ence of a basiccatalyst to yield diphenyl butyl phosphite. C1 This phosphite may thenbe reacted with a polyol to form 0 OCHZ CHzOH a predominantly cyclicphosphite product. Examples of H alcohols which may be so utilized aremethanol, ethanol, C propanol, decanol, stearyl alcohol, isomers thereofand so or 0 CH2 onion forth. 12) In the preparation of the polyurethanecompositions OH CH2OH OH containing the novel esters of phosphonic aciddisclosed in Catalytic this invention, it is preferred to use ahydroxyl-containing CH3 CH2 $H([J CHZO P CAJJHAJHPC'H' polymericmaterial having 1 hydroxyl number from about H01 0-0132 H0 25 and about900. Such a polymeric material can be a OH CHZOH 0 0-011: OH pol ester,a olyether or mixtures thereof. Particularl u y J; J sultable aremixtures of a polyester and a polyether wherel in the olyester portioncomprises at least 25 percent of HO 0-011, HO p where Z is as definedabove,

wherein X is a halogen selected from the group consisting of iodine,bromine, and chlorine and alkyl is a hydrocarbon containing from 1 to 32carbon atoms. Polymers of these monomers may also occur.

The reactions given illustrate various features of the invention, therebeing many more variations. The reactions of this invention may becarried out at temperatures of 25 degrees to 300 degrees Centigrade. Thepreferred temperature range is between 75 degrees and 200 degreescentigrade, with a more preferred range being between 160 and 200degrees Centigrade. The preparation of the phosphites, as well as theArbuzov rearrangement are carried out at temperatures within the rangeset forth above. However, it is to be understood that the temperatureemployed may be varied when subatmospheric and superatmosphericpressures are utilized. The preparation of the cyclic or bicyclicphosphites does not require a transesterification catalyst when thepreparation of the phosphonate is to be carried out in situ. However,the preparation of the phosphites may be accelerated by utilizing atransesterification catalyst, e.g., a metal alcoholate, phenolate orhydride, such as sodium methylate, lithium methylate, potasiummethylate, sodium ethylate, sodium isopropylate, sodium phenolate,potassium phenolate, sodium cresylate, sodium hydride, sodium metal,lithium metal and so forth, and diesters of phosphorous acid. It ispreferred that the basic transesterification catalyst utilized have a pHof at least 7.5 in a 0.1 normal solution to be utilized in the reaction.

The Arbuzov rearrangement is deemed completed on obtaining a negativeresult in the iodine test for phosphite.

The starting phosphite from which the cyclic and bicyclic phosphites areto be prepared may be varied, depending upon the polyols and reactingphosphites to be utilized. It is to be understood that depending on thethe mixture. Excellent results are obtainable when less than 25 percentpolyester is employed, but supplementary additives may be required torender such a foam selfextinguishing. It is especially preferred in thepresent invention to use a mixture of polyester and polyether in theratio of 25 to parts polyester to 75 to 25 parts of polyether.Generally, the hydroxyl-containing polymers have a molecular Weight inthe range from 200 to about 4,000.

The polyesters are the reaction products of a polyhydric alcohol and apolycarboxylic compound, said polycarboxylic compound being either apolycarboxylic acid, a polycarboxylic acid anhydride, a polycarboxylicacid ester, a polycarboxylic acid halide or mixtures thereof. Thecarboxylic compounds can be aliphatic, cyclo aliphatic, aromatic, orheterocyclic and either saturated or unsaturated. Among thepolycarboxylic compounds which can be used to form the polyester are:maleic acid; fumaric acid; phthalic acid; isophthalic acid; terephthalicacid; tetrachlorphthalic acid; aliphatic acids such as oxalic, malonic,succinic, glutaric and adipic; 1,4-cyclohexadiene- 1,2-dicarboxylic acidand the like. Additional polycarboxylic compounds which can be used toform the polyester are Diels-Alder adducts of hexahalocyclopentadieneand a polycarboxylic compound, wherein the halogen is selected from thegroup consisting of chlorine, bromine, fluorine and mixtures thereof,for example: l,4,5,6,7,7- hexachlorobicyclo-( 2,2,1)-5-heptene-2,3-dicarbo-xylic acid;1,4,5,6-tetrachloro-7,7-difluorobicyclo-(2.2.1)-5 heptene- 2,3dicarboxylic acid; 1,4,5,6,7,7 hexabromobicyclo- (2.2.l)-5-heptene 2,3dicarboxylic acid; l,4,5,6tetrabromo-7,7-difluorobicyclo-(2.2.1)-S-heptene 2,3 dicarboxylic acid;and the like. Mixtures of any of the above polycarboxylic compounds canbe employed. In order to obtain a satisfactory rigid foam, at least aportion of the total polyhydric alcohol component should consist of apolyhydric alcohol containing at least three hydroxyl groups. This isdesired to provide a means for branching the polyester. Where an evenmore rigid structure is desire, the whole alcohol component may be madeup of a trifunctional alcohol such as glycerol. Where a less rigid finalproduct is desired, a difunctional polyhydric alcohol such as ethyleneglycol or 1,4-butanediol may be utilized as that part of the polyhydricalcohol component. Other glycols such as diethylene glycol, triethyleneglycol, propylene glycol, dipropylene glycol, other polypropyleneglycols, butylene glycols, polybutylene glycols, and the like can alsobe used. Among the polyhydric alcohols which can be used are glycerol,hexanetriol, butanetriol, trimethylol propane, trimethylol ethane,pentaerylthritol, mannitol, sorbitol, cyclohexanediol-l,4-glycerolmonoethyl ether and the like. The ratio of the polyhydric alcohol suchas glycerol to the polybasic acid can be expressed as thehydroxyl-carboxyl ratio, which can be defined as the number of moles ofhydroxyl groups to the number of moles of carboxyl groups in a givenweight of resin. This ratio may be varied over a wide range. Generally,however, a hydroxyl-carboxyl ratio of between 1.5:1 to :1 is needed.

Instead of employing a polycarboxylic compound which is Diels-Alderadduct of hexahalocyclopentadiene and a polycarboxylic compound, apolyhydric alcohol which is a Diels-Alder adduct ofhexahalocyclopentadiene and a polyhydric alcohol can be used. This isdone by employing (A) a polyester resin comprised of the reactionproduct of (1) an adduct of hexahalocyclopentadiene and a polyhydricalcohol containing aliphatic carbon-to-carbon unsaturation, (2) apolycarboxylic compound and (3) a polyhydric alcohol containing at leastthree hydroxyl groups. Typical adducts include: 2,3-dimethylol-1,4,5,6,7,7 hexachlorobicyclo-(2.2.1)-5-heptene; and2,3-dimethylol-l,4,5,6-tetrachloro-7,7-difluorobicyclo-(2.2.1)-5-heptene.Similar compounds are disclosed in US. Pat. 3,007,958.

Where aromatic or bicyclo carboxylic compounds are used, aliphatic acidsare sometimes incorporated into the polyester resin. Adipic acid isgenerally preferred for this purpose, although other suitable acids maybe used such as oxalic, malonic, succinic, glutaric, pimelic, suberic,azelaic, etc. Unsaturated acids such as maleic, fumaric, itaconic,citraconic, aconitic, etc., can also be used.

The preferred polyesters are those which contain an adduct ofhexahalocyclopentadiene co-reacted in the polyester portion in view ofthe fact that they contain a large amount of stable chlorine, therebyenhancing the flameretardant characteristics of the resultant foam.Particularly preferred are those polyesters wherein the adduct isreacted in the polycarboxylic portion of the polyester, due to lowercost and commercial availability of the polycarboxylic adducts ofhexahalocyclopentadiene.

The polyethers employed are known in the art, and are the reactionproducts of (1) either a polyhydric alcohol, a polycarboxylic acid or apolyphenolic compound, and (2) a monomeric 1,2-epoxide possessing asingle 1,2-epoxy group, such as, for example, propylene oxide. Thepolyhydric alcohols and polycarboxylic acids which may be employed areany of the polyhydric alcohols and polycarboxylic acids hereinbeforelisted. Polyphenolic compounds which can be employed are the reactionproducts of phenolic compounds with aldehydes, such asphenol-formaldehyde resins. Examples of monomeric 1,2-epoxides includeethylene oxide, propylene oxide, butylene oxide, isobutylene oxide,2,3-epoxyhexane, 3-ethyl-2,3-epoxyoctane, epichlorohydrin,epibrornohydrin, styrene oxide, glycidyl ether, methyl glycidyl ether,phenyl glycidyl ether, butyl glycidyl sulfide, glycidyl methyl sulfone,glycidyl methacrylate, glycidyl acrylate, glycidyl benzoate, glycidylacetate, glycidyl octanoate, glycidyl sorbate, glycidyl allyl phthalate,and the like. The preferred monoepoxides are the monoepoxide substitutedhydrocarbons, the monoepoxy-substituted ethers, sulfides, sulfones andesters wherein the said compounds contain no more than eighteen carbonatoms. A lower alkylene oxide is preferably employed in rigid foams asthe higher counterparts yield flexible rather than rigid products.

A large number of different organic polyisocyanates can be used. Of thehydrocarbon polyisocyanates, the aryl and alkaryl polyisocyanates of thebenzene and naphthalene series are more reactive and less toxic than thealiphatic members. Consequently, the aromatic compounds are preferred inthe present invention. The preferred compounds which are at present mostreadily available commercially are 2,4-tolylene diisocyanate,2,6-t0lylene diisocyanate and mixtures thereof. However, others may beused, among them phenyl diisocyanate;

alpha-naphthyl diisocyanate; 4-tolylene diisocyanate;

n-hexyl diisocyanate; methylene-bis-(4-phenyl isocyanate);3,3-bitolylene-4,4'-diisocyanate; 3,3-dimethoxy-4,4-biphenylenediisocyanate; 1,5-naphthalene diisocyanate; 2,4-chlorophenyldiisocyanate; hexamethylene diisocyanate;

ethylene diisocyanate;

trimethylene diisocyanate; 1,3-cyclopentylene diisocyanate;1,2-cyclohexylene diisocyanate; 1,4-cyclohexylene diisocyanate;cyclopentylidene diisocyanate; cyclohexylidene diisocyanate; p-phenylenediisocyanate; m-phenylene diisocyanate; 4,4-diphenyl propanediisocyanate; 4,4-diphenyl methane diisocyanate; l-methyl-2,4-phenylenediisocyanate; 4,4-diphenylene diisocyanate; 1,2-propylene diisocyanate;1,2-butylene diisocyanate;

ethylidene diisocyanate;

propylidene diisocyanate;

butylidene diisocyanate;

1,3,5-benzene triisocyanate; 2,4,6-tolylene triisocyanate;2,4,6-monochlorobenzene triisocyanate; 4,4,4"-triphenylmethanetriisocyanate; polymethylene polyphenylisocyanate and mixtures thereof.

Higher isocyanates are provided by the liquid reaction products of (l)diisocyanates and (2) polyols or polyamines; etc. In additionisothiocyanates and mixtures of isocyanates may be employed. Alsocontemplated are the many inpure or crude polyisocyanates that arecommercially available, such as crude mixtures of methylene bis(4-phenylis0cyanate).

The catalyst employed can be any of the known conventional catalysts forisocyanate reactions, such as tertiary amines, for example,triethylamine, N-methyl morpholine, triethanolamine, etc., or antimonycompounds such as antimony caprylate, antimony naphthenate, orantimonous chloride. In addition, tin compounds can be employed such asdibutyltin dilaurate, tri-n-octyltin oxide, hexabutylditin, tributyltinphosphate, or stannic chloride. Phosphorus acids, such as the alkyl acidphosphates, can also be employed. Rigid or flexible polyurethane foamsare thereby obtained. The rigid polyurethane foams utilize a highlybranched hydroxyl rich polyester or polyether having a hydroxyl numberof between about two hundred and nine hundred and fifty. The flexiblepolyurethane foams utilize a linear relatively hydroxyl poor polyesteror polyether having a hydroxyl number of between about thirty and onehundred. If a polyester or polyether with a hydroxyl number betweenabout one hundred and two humdred is employed, a semi-rigid polyurethanefoam is usually obtained.

Any foaming agent commonly used in the art can be employed. Foamingagents in this art are generally those materials that are capable ofliberating gaseous products when heated, or when reacted with anisocyanate. Preferably foaming is accomplished by introducing a lowboiling liquid into the catalyzed resin. The heat of reaction is thensufiicient to expand the mixture to a foam stable enough to retain itsshape until the resin gels. Suitable liquids are the fiuorochlorocarbonsboiling in the range of twenty to fifty degrees centigrade, and mixturesthereof, for example, trichlorofluoromethane, trichlorotrifiuoroethane,dichloromofiuoromethane, monochloroethane, monochloromonofluoroethane,dichloromonofluoroethane, and difiurodichloroethane.

Another foaming system that is suitable for carrying out the foamingreaction at an elevated temperature is found in United States Pat.2,865,869, which discloses and claims the use of tertiary alcohols inthe presence of strong, concentrated acid catalysts. Examples oftertiary alcohols include: tertiary amyl alcohol; tertiary butylalcohol; 2- methy1-3-butyn-2-ol; l-methyl-l-phenylethanol; and 1,1,2,Z-tetraphenylethanol, etc. Examples of catalysts include: sulfuric acid;phosphoric acid; sulfonic acid; and aluminum chloride; etc. In addition,various secondary alcohols and glycols may be used as:1-phenyl-1,2-ethanediol; 2- butanol; etc. Generally, secondary alcoholsshould be used with strong concentrated acid catalysts as above;however, certain secondary alcohols may be used without the acidcatalyst, e.g., acetaldol, chloral hydrate, etc. Other foaming agentsthat may be used include the following: polycarboxylic acids,polycarboxylic acid anhydrides, dimethylol ureas, polymethylol phenols,formic acid and tetra (hydroxymethyl) phosphonium chloride. In addition,mixtures of the above foaming agents can be employed.

In preparing the polyurethane compositions of this invention, thehydroxyl containing polymer, either alkyd resin or polyether, andpolyisocyanate are preferably reacted in a ratio sufiicient to provideabout eighty-five to one hundred and fifteen percent of isocyanatogroups with respect to the total number of hydroxyl and carboxyl groupspresent in the hydroxyl-containing polymeric material (and the foamingagent, if one is provided). The reaction temperature generally rangesfrom about twenty to about one hundred and twenty degrees centigrade,although higher and lower temperatures can be used.

The phosphonates of the present invention may be utilized in the rangeof from about 0.2 to 30 percent of the polyol component contained in theUrethane Foam System; however, the preferred range being from about 5 toabout 25 percent, with best results for flame-retarding being obtainedwhen from to percent of the polyol component contained in the UrethaneFoam System is the novel esters of phosphonic acid of the presentinvention. The Urethane Foam System described above does include theweight of the blowing agent, catalyst, and surfactant.

The polyol phosphonate may be blended by means known to the art with theother components of the Urethane Foam System at temperatures rangingfrom 0 to about 150 degrees centigrade-although usually temperatures of-50 degrees centigrade are utilized.

In addition to the polyurethane the phosphonates of this invention maybe utilized as flame-retarding additives or reactants in other plasticsystems, such as the polyesters, polyacrylates, poly-methacrylates,polyepoxides, polyvinylchlorides, phenylaldehyde polymers, polyamides,and so forth.

The following examples illustrate the invention, but do not limit it.All parts are by weight and temperatures are in degrees centigradeunless otherwise stated.

EXAMPLE 1 Triphenyl phosphite (4 gram moles), n-butanol (8 gram moles),and NaH (2 grams) were reacted in.a

vessel for two hours at a temperature of 120 degrees centigrade.Pentaerythritol (4 moles) was then added to the reaction vessel. Atemperature of degrees centigrade was maintained for three hours todissolve the pantaerythritol in the reaction mixture. To assuretransesterification, sodium hydride (1 gram) was added and the reactionmixture was heated at degrees centigrade for two hours. An Arbuzovrearrangement was accomplished by adding butyl bromide (63 grams) to thereaction mixture and heating the mixture at 153 degrees centigrade untilno residual phosphite was observed by iodine titration. A yellowishliquid of syrupy consistence was obtained after distillation ofvolatiles at about 100 degrees centigrade under vacuum of from 10 to 50millimeters of mercury. Infrared analysis indicated the structure of thecompound to be CHeOH In the subsequent examples moles are defined asgram moles.

EXAMPLE 2 Dibutyl phenyl phosphite (8.48 moles), dissolved in solventphenol (1420 grams), and pentaerythritol (8.48 moles) were placed in areaction vessel. This reaction mixture was heated to about degreescentigrade and maintained at about this temperature for about one hourto obtain a liquid reaction mixture. Sodium hydride (4 grams) was thenadded and the reaction mixture was heated to degrees centigrade andmaintained at about this temperature for a period of about two hours.Butylbromide (338 grams) was then added to the reaction mixture. Thismixture was maintained at a temperature of from about to 154 degreescentigrade for approximately 14.5 hours, until a negligible iodine titerfor phosphite was obtained. The volatiles were separated as inExample 1. The results of infrared analysis indicated the structure ofthe viscous yellow product to be 0 O-CHz CHzOH CHgOH Pentaerythritolbutane phosphonate A 97.5 percent yield was obtained based on dibutylphenyl phosphite.

EXAMPLE 3 CHaOH The product was analysed for precent phosphorus. Found:12.6 percent phosphorus. Calculated: 13 percent phosphorus.

A 95.5 percent yield, based on dibutylphenyl phosphite, was obtained.The theoretical molecular weight of this composition is 238 and theactual molecular weight found in acetone was 238.

1 9 EXAMPLE 4 Triphenylphosphite (10 moles), butanol (20 moles), andsodium hydride (6 grams) were reacted in a vessel at about 135 degreescentigrade for 2.5 hours. Pentaerythritol (10 moles) and solvent phenol(1,675 grams) were added to the mixture and the mixture was heated for2.5 hours at about 135 degrees centigrade. An additional 6 grams ofsodium hydride were added to the reaction mixture during this time toincrease the rate of reaction. Ethylene chlorohydrin 10 moles) was addedto the reaction mixture and the mixture was heated to reflux temperature(pot temperature between about 153 and 167 degrees centigrade) for aperiod of 20.5 hours. At the end of this time, a negligible iodine titerwas obtained. Infrared analysis indicated that the structure of theproduct obtained, after distilling the volatiles as in Example 1,

was

The product was viscous, had a yellowish appearance and was obtained in92 percent yield, based on triphenylphosphite.

EXAMPLE 5 Triphenyl phosphite (1.5 moles), dipentaerythritol (1.5moles), phenol solvent (847 grams) and 25 percent sodium methoxide inmethanol (3.3 grams) were mixed in a vessel and heated for approximately12 hours at from about 125 to 160 degrees centigrade to effect solutionand reaction. The reaction mixture was vacuum stripped of by-productphenol at about 20 millimeters mercury absolute pressure at about 100degrees Centigrade leaving a residue of the product, dipentaerythritolmonophosphite. It was obtained in nearly theoretical yield as a hard waxwith a melting point of about 115 degrees Centigrade. Infrared analysisof this product showed that the phosphite formula was consistent withstructure OOH POCH2CCH2O-O H2-C (CHgOH);

OCH2

Dipentaerythritol monophosphite. Phosphorus analysis was: Calculated,percent phosphorus, 11; actual, percent phosphorus, 10.

EXAMPLE 6 Dipentaerythritol monophosphite (1 mole) prepared inaccordance with Example 5, was dissolved in dimethyl formamide (252grams) and isomerized (rearranged) with decyl bromide (1 mole) at 158degrees centigrade for 50 hours. By-product volatiles was then vacuumstripped at about 55 degrees centigrade at 15 millimeters mercurypressure, absolute. The product was found to be free of the startingphosphite, by iodine titration. Infra red analysis of the residueindicated the structure of the product to be:

/ C\ -CH2OH -052 C1120 CH2 lla 20H Bromodipentaerythritol decanephosphonate EXAMPLE 7 Utilizing the dipentaerythritol monophosphite (1mole) of Example 5, dimethyl formamide solvent (118 grams) andchloromethylethyl furoate (1 mole), the correspondingchlorodipentaerythritol-S-methylene-ethyl furoate phosphonate wasobtained after heating the mixture for from 45 to 60 hours at from 158to 175 degrees centigrade with vacuum distillation of volatiles at aboutmillimeters of mercury at about 160 degrees centigrade. This phosphonatewas shown to be free of starting phos- 20 phite by iodine titration. Theproduct was subjected to infra red analysis and indicated the structureto be In the following examples, when the procedure of Example 7 isfollowed, using the indicated reactants, the products obtained are asindicated.

CHzCl EXAMPLE 8 Reactants: Moles Dipentaerythritol monophosphite 1Benzyl chloride 1 Product:

(fi/OCH2 /OH2O1 CHTP Chlorodipentaerythritol benzyl phosphonateChlorodipentaerythritol furfuryl phosphonate EXAMPLE 10 Reactants: MolesTriphenyl phosphite 1 Dipentaerythritol monophosphite 1 The process ofExample 5 for formation of the dipentaerythritol monophosphite wasrepeated except that the phenol was not isolated from the phosphiteproduct.

EXAMPLE 11 Reactants: Moles Triphenyl phosphite 1 Dipentaerythritol 1Benzyl bromide 1 The process of Example 6 for the preparation ofbrornodipentaerythritol decane phosphonate was repeated and thephosphonate was formed in situ without first stripping the phenolby-product formed. The phosphonate product was isolated after vacuumstripping of volatiles as in Example 6. The product formed, as indicatedby infra red analysis has the structural formula:

EXAMPLE 12 Reactants: Moles Triphenyl phosphite 1 Dipentaerythritol 15-chloromethyl-ethy1 furoate 1 When the process of Example 11 isrepeated with the above reactants, correspondingchlorodipentaerythritol- 5--methylene-ethyl furoate phosphonate wasrecovered having the following structure as the final product.

21 Phosphorus analysis were: Calculated, percent phosphorus, 6.6;actual, percent phosphorus, 6.0.

EXAMPLE 13 Reactants: Moles Triphenyl phosphite 1 Dipentaerythritol 1Benzylchloride 1 When the process of Example 11 is repeated with theabove reactants, corresponding chlorodipentaerythritol benzylphosphonate is formed. The structural formula may be indicated by:

fi/O-C'Ez /CH2C1 0112-? O-CH2 CH2OCH2C (OHzOH);

EXAMPLE 14 Reactants: Moles Triphenyl phosphite 1 Dipentaerythritol 1Furfuryl chloride 1 When the process of Example 11 is repeated thecorresponding chloro-dipentaerythritol furfuryl phosphonate:

will be recovered.

EXAMPLE 15 Pentaerythritol phosphite, HOCH C(CH O) P, was prepared as aWhite crystalline product by the sodium methoxide catalysis of triphenylphosphite (1 mole) with entaerythritol (1 mole), utilizing a phenolsolvent. The entaerythritol phosphite was obtained in 85 percent yield.The by-product phenol was stripped by distillation at 115 degreescentigrade under 3 millimeters of mercury absolute. The product had amelting point of about 62 degrees centigrade. Phosphorus analysis were:Calculated, percent phosphorus, 18.9; actual, percent phosphorus, 19.1.

Infrared data indicates the identity of the product to be entaerythritolphosphite as set forth above.

In a like manner when tripentaerythritol is substituted fordipentaerythritol, tripentaerythritol phosphite having a structuralformula is obtained.

EXAMPLE 16 Reactants: Moles Pentaerythritol phosphite 41,4-bischloromethyl benzene 1 The reaction mixture was held in the rangeof 150- 210 degrees centigrade until iodine titration indicated that nophosphite remained. Bis-chloropentaerythritol xylylene diphosphonate wasrecovered as the final product after stripping the distillates at fromabout 160 degrees centigrade. The product was white and glasslike inappearance and had a melting point of from about to 108 degreescentigrade.

Phosphorus analysis were: Calculated, percent phosphorus, 12.32; actual,percent phosphorus, 12.1.

In the following examples, when the process of Example 16 is followedthe products obtained with the reactants mentioned are as indicated.

EXAMPLE 17 Reactants: Moles Pentaerythritol phosphite 23,3-bisiodomethyl oxetane 1 Product:

ICHz oH2-o\(") o O-GH: CH2]:

PCH2C-CH2--i HOCH: GHQ-o C 2 CH2 O-GH: CHzOH Bis iodopentaerythritol-3,3bismethylene oxetane diphosphonate EXAMPLE 18 Reactants: MolesPentaerythritol phosphite 2 Trimethylene bromide 1 Product:

BrCHz CHE-o 0 o O-GH CHB \u u/ 2 r PCHzCH2CHzP H0 0E1 CH2--O 043E:\CH2OH Bis-bromopentaerythritol trimethylene diphosphonate EXAMPLE 19Reactants: Moles Tripentaerythritol monophosphite 1 Decyl bromide 1Product:

fi/O-C32 /GHzBr CHa(CH2)D-P\ C\ CHzOH CHzO o-cg CHzOCHziJCHrOCHz?-CH2OHHzOH CHzOH Bromotripentaerythritol decane phosphonate EXAMPLE 20Reactants: Moles Tripentaerythritol monophosphite 1 Benzyl chloride 1Product:

l)/OC& /CH2G1 CHz-P CHzOH 0-0112 CH2-O-CH2-CCHBOCH2C(CH2OH)3 CHzOHChlorotrlpentaerythritol benzyl phosphonate 23 24 EXAMPLE 21 Product:

Reactants: Moles OH 01120}?! 0 2 N02 Tripentaerythritol monophosphite 1L Furfuryl chloride 1 Product: 5 NO: OCH2 CH-CH2-'CH3 bo-0% /CH2C1/CH2-P 0 0112011 0 0-011: CHn-O-CHz-OOH2OCHzC-C(CHgOH):

CHzOH Chlorotripentaerythritol furfuryl phosphonate EXAM L 27 EXAMPLE 22Reactants: Moles Reactants: Moles Triphenyl phosphite 1Tripentaerythritol monophosphite 1 1,1,1,3,3,3-he xamethylo1propanol-(2) 2 S-chloromethyl-Z-ethyl furoate 1 Benzyl chl rlde 1Product:

o I o-cg; /GH2C1 CzHgO] /-CH2P CHzOH 0-0 2 OHz-O-CH2 'CHT-OCHBC(OHZOH)3CHzOH Chlorotripentaerythritol-5-methy1ene-2ethy1 furoate ph'osphonateEXAMPLE 23 Product: Reactants: Moles 9 /CH2Gl Tripentaerythritolmonophosphite 1 Butyl iodide 1 l O-CH CH- Product: 2 C(CHQOH) 0H /CH2IChloro-l 1 1 3 3 3-hexamethylol propanol-2-benz 1 phos honate cum-1 o(IJHZOH 0112011 y p o-ofi OHzOCHz-CCH2OOHa-C-CH2OH CHzOH CHZOH EXAMPLE23 Iodltrlpentaerythritol butane phosphonate Triphenyl phosphtte (20moles) and trimethylol pro- EXAMPLE 24 pane (40 moles) were reacted in areaction vessel for about one hour and thirty minutes at a temperatureof fgq thritol mono hos bite Mole: 40 135 degrees centigrade. Thereaction mixture was then m mi d e P p 1 heated to a temperature betweenabout 185 degrees and P d 205 degrees centigrade and maintained at thistemperature m for a period of 9 hours to effectuate thermalisomerization R 0112131 as indicated by a negligible iodine titer. Theproduct cmwrm ql 0 03,011 01 ,0 formed was isolated by distilling phenoltherefrom at 125 \CHZOCH2-C CH2 O GHZ G CHZOH degrees centlgrade under apressure of 10 rmlltmeters of mercury absolute. HYOH H8011 According totheory and an infrared analysis thereof,

Bromotrlpentaerythritol octadecane phosphonate the product formed was ofthe structure:

EXAMPLE 25 Reactants: Moles 02H; 0 02115 Tripentaerythritolmonophosphite 1 H0 J Allyl bromide 1 Product: CHz-O H2OH fi/O-Gg: 0H201CH=CHCH2P o CHZOH 0-orn CHZ-O-GHQ- -oH,-ooHg-o oH,oH)a

HzOH

Alkyl phosphinate EXAMPLE 29 Bromotripentaerythritol allyl phosphonateFollowing the teachings of Example 2 the following products are formedfrom the reactants indicated in Examples 26 and 27.

EXAMPLE 26 Reactants: Moles Triphenyl phosphite 12-nitro-2-hydroxymethyl hexane diol-(1,3) 2 Hexyl chloride 0.1

The phosphonate formed in accordance with Example 28 was incorporatedinto a polyurethane foam system as follows:

Polyester A polyester was prepared by the esterification of 10 moles(1340 parts) of trimethylol propane with 60 moles (877 parts) of adipicacid. The resin thus formed had a hydroxyl number of 504.

25 Mixture A To 70 parts of the above described polyester resin thefollowing was added:

Parts Polyol phosphonate prepared in accordance with Example 28 30Trichlorofiuoromethane 28 Silicone surfactant, such as silicone X-5200.5 Tetramethyl butane diamine 0.8

The ingredients were then mixed until a homogeneous mixture wasobtained.

Prepolymer A prepolymer was prepared by the addition of 20 parts of theabove described polyester to 80 parts of toluene diisocyanate (a mixtureof 80% 2,4-toluene diisocyanate, and 20% 2,6-toluene diisocyanate). Thismixture was heated at 80-100 degrees centigrade for /2 hour.

The above prepolymer (117 parts) was added to 129.3 parts of Mixture A.They were mixted for 30 seconds and the mixture was poured to yield afine, closed-celled rigid foam. This foam had the following physicalproperties:

Density: 2.33 pounds per cubic foot Compressive yield pressure: 29.2pounds per square inch Underwriters Laboratory Flame Test UL484: 108.2seconds per 2.96 inches burned. (A modified American Society for TestingMaterial D1692-59T.)

EXAMPLE 30 A foam prepared by the above procedure without thephosphonate of Example 28 present had the following properties:

Density: 2.23 pounds per cubic foot Compressive yield pressure: 30.9pounds per sq. in. UL-484 Test: 152 seconds for an entire 6" specimen.

The results of Examples 29 and 30 indicate that the polyol phosphonatepolyurethane foam composition of this invention is fire retardant, whilealso retaining the desirable density and compressive yield properties ofsuch a material without the polyol phosphonate.

EXAMPLE 31 The following reactants were mixed in a reaction vessel andheld for about two hours at 135 degrees centigrade, with stirring:

Triphenyl phosphite4 moles (1240 parts) n-Butanol8 moles (592 parts)Trimethylol propane-5 moles (671 parts) Sodium hydride2 parts To theabove mixture, after about two hours, was added 4 moles (322 parts) ofchlorohydrin, and the resulting mixture was then refluxed about 6 hoursat 135 degrees centigrade.

The butyl chloride Was then distilled off at atmospheric pressure untila pot temperature of 175 degrees centigrade was reached. After removingthe butyl chloride, the residual contents of the reaction mixture wasfound to have a negligible iodine titer, i.e., less than 1.0 percent ofthe original titer.

The remaining butyl chloride, excess butanol, by-product phenol andother volatiles were removed under decreasing vacuum conditions until anultimate pot temperature of about 160 degrees at 3 millimeters ofmercury absolute was achieved.

The residual product was a phosphonate of structure:

m e HO CHzCHz-P CCH2OH O-CHz OHzCH Trimethylol Propane HydroxyethylPhosphonate 26 A slight acidity in the resulting phosphonate waseliminated by refluxing with excess propylene oxide (340 parts of theabove phosphonate, with 673 parts of propylene oxide) for about 6 hoursat 37 degrees centigrade pot temperature. The residue was removed at atemperature of 140 degrees centigrade at 25 millimeters of mercury.

This residue corresponded to trimethyl propane hydroxyethyl phosphonate.

EXAMPLE 32 The phosphonate formed in accordance with Example 31 wasincorporated into a polyurethane foam system as follows:

Polyester This polyester was prepared in accordance with Example 29,substituting the phosphonate of Example 31.

Mixture B To 60 parts of the polyester described in Example 29 thefollowing were added:

Parts Phosponate of Example 31 40 Trichlorofiuoromethane 28 Siliconesurfactant, such as Silicone X-520 (made by Union Carbide Co.) 0.5Tetramethyl butane diamine 0.8

The ingredients were then mixed until homogeneity was obtained.

The prepolymer of Example 29 (125 parts) was added to Mixture B. A foamwas formed in a manner similar to that disclosed in Example 29. Thisfoam had a flame retardance of 36.2 seconds per 1.14 inches burned asindicated by Underwriters Laboratory Test 484.

EXAMPLE 33 Triphenyl phosphite (4 moles, 1240 parts), n-butyl alcohol (8moles, 593 parts) and sodium hydride (2 parts) were charged to areaction vessel and transesterified for about two hours at 120 degreescentigrade. After about two hours, pentaerythritol (4 moles, 544 parts)was added to the mixture. This mixture was heated at about degreescentigrade for about three hours to dissolve the pentaerythritol.Transesterification was accomplished by adding 1 part of sodium hydrideto this mixture and heating at about degrees centigrade for about 2hours. After this time, butyl bromide (63 parts) was added to thereaction vessel. The mixture formed was then heated at degreescentigrade until an iodine titer of less than about one percent of thestarting iodine titer was obtained. The product was viscous and yellowin appearance. The structure of the phosphonate formed is OHzOH Infraredanalysis of this compound gives evidence to support this structure.

EXAMPLE 34 A urethane foam incorporating the phosphonate prepared inaccordance with .Example 32 was prepared as follows:

Polyester The polyester was prepared by the esterification of 1 mole(134 parts) of trimethylol propane with 0.75 mole (292 parts) of HETAcid (1,4,5,6,7,7-hexachlorobicyclo(2.2.1)-5-heptene-2,3-dicarboxylicacid). This mixture was heated to 75 degrees centigrade and thenpropylene oxide (262 parts) was added. The temperature was thenmaintained at 100 degrees centigrade for 5 hours. Unreacted propyleneoxide was distilled out at 103 degrees centigrade at 4 millimeters ofmercury absolute. The hydroxyl number of this polyester was 263.

Mixture C To 80 parts of the above polyester were added 20 parts of thephosphonate prepared as in Example 33.

Trichlorofiuoromethane Silicone surfactant, e.g. X-52O Silicone (made byUnion Carbide Co.)

Dibutyl tin dilaurate 1 To 130 parts of the above Mixture C were added66 parts of toluene diisocyanate. This was mixed 30 seconds to form afine-celled rigid foam. This foam showed marked improvement inflame-retardance over a similar polyurethane foam without the polyolphosphonate, as indicated by an American Society for Testing MaterialTest D757 value of 0.755 inch per minute for the phosphonate-containingfoam.

EXAMPLE 35 This example illustrates the retardation of flame andafter-glow in varnishes which incorporate the phosphonates of thepresent invention:

(A) Preparation of alkyl.Pentaerythritol butane phosphonate (307),prepared in accordance with Example 2, a distilled, soya, fatty acid(317 parts), e.g., Emery 618, and phthalic anhydride (116 parts) weremixed in a reaction vessel and heated at a temperature of about 200degrees centigrade for approximately seven hours. The acidity in themixture was removed by treatment with epichlorohydrin.

(B) Preparation of varnish.-The above prepared alkyd (102.5 parts) wasblended with xylene (102.5 parts) lead naphthenate (.08 part of a 25%solution of lead naphthenate in xylene and cobalt naphthenate (.3 part)of a 6 percent solution of cobalt naphthenate in xylene.

This formulated varnish was painted on small wooden pine strips 3 inchesby 4 inches Which were then oven cured to a hard film at 80 degreescentigrade for 10 hours.

When tested, the wooden strips painted with the above formulated polyolphosphonate varnish exhibited a high degree of flame-retardance, whencompared with the untreated controls.

Also significant was the lack of after-glow in the painted woodenstrips, as compared with the after-glow which appeared in tests run withuntreated wooden control specimens.

While the invention has been set forth in the above description andexamples, it should be realized that in its broadest aspects, theinvention is not so limited. Many modifications will become apparent toone skilled in the art upon a reading of this disclosure.

What is claimed is:

1. An ester of phosphonic acid, of the formula having from 4 to 54carbon atoms and from 2 to 11 hydroxyls, wherein M is a residue of apolyol wherein two hydroxyls are removed from carbon atoms withhydroxyls attached thereto and with a carbon atom between the two carbonatoms from which the hydroxyl groups have been removed, said polyolbeing of 3 to 15 carbon atoms and having from 4 to 8 hydroxyl groups, Ais selected from the group consisting of alkyl of 1 to 10 carbon atoms,cycloalkyl of 5 to 6 carbon atoms, hydrocarbyl aryl of 6 to 18 carbonatoms, monohalophenyl, dihalophenyl, lower alkyl phenyl, lower alkylnaphthyl, phenyl-lower alkyl, hydroxy-lower alky, containing from 1 to 4hydroxyls, hydroxy-lower alkoxy-lower alkyl, containing from 1 to 5hydroxyls, lower alkylene, monochloro-lower alkylene, mononitro-loweralkylene, phenyl-lower alkylene, cyclohexyl-lower alkylene,dichloro-lower alkylene, and hydroxy-lower alkylene, containing up to 3hydroxyls,

alkoxyalkyl wherein the alkoxy and alkyl radicals are each of up to 10carbon atoms, lower alkoxy cycloalkyl, wherein the cycloalkyl is of 5 to6 carbon atoms, lower alkene, and cycloalkene, wherein the cyclicradical is of 5 to 6 carbon atoms, and n is from 0 to 5.

2. An ester of phosphonic acid of the formula having from 4 to 54 carbonatoms and from 2 to 11 hydroxyls, wherein R is independently selectedfrom the group consisting of hydrogen, alkyl of 1 to 10 carbon atoms,lower alkyl substituted phenyl, phenyl substitutedlower alkyl, nitro,chloromethyl, bromornethyl, iodomethyl, monohalophenyl, dihalophenyl,hydroxy-lower alkyl, containing from 1 to 4 hydroxyls, phenyl,alkoxyalkyl, wherein the alkoxy and alkyl radicals are each of up to tencarbon atoms, hydroxy-lower alkoxy-lower alkyl, containing from 1 to 5hydroxyls, lower alkene, lower alkyl substituted lower alkene,monohalosubstituted alkene, Z is selected from the group consisting ofalkyl of 1 to 10 carbon atoms, lower alkylene, lower alkene phenylsubstituted lower alkyl, phenyl, lower alkyl substituted phenyl,monohalophenyl, dihalophenyl, hydroxyl substituted lower alkylcontaining from 1 to 4 hydroxyls, hydroxyl substituted lower alkylenecontaining up to three hydroxyls, monohalosubstituted lower alkylene,monohydroxyl substituted phenyl, monohydroxy phenyl substituted loweralkyl, and monohydroxy-lower alkyl substituted phenyl, and n is from 0to 5.

3. An ester of phosphonic acid of the formula having from 4 to 54 carbonatoms and from 4 to 11 hydroxyls, wherein M is a residue of a polyolwherein two hydroxyls are removed from carbon atoms with hydroxylsattached thereto and with carbon atoms between the two carbon atoms fromwhich the hydroxyl groups have been removed, said polyol being of 3 to15 carbon atoms and having from 4 to 8 hydroxyl groups, and A isselected from the group consisting of alkyl of 1 to 10 carbon atoms,cycloalkyl of 5 to 6 carbon atoms, hydrocarbyl aryl of 6 to 18 carbonatoms, monohalophenyl, dihalophenyl, lower alkyl phenyl, lower alkylnaphthyl, phenyl-lower alkyl, hydroxy-lower alkyl, containing from 1 to4 hydroxyls, hydroxy-lower alkoxy-lower alkyl, containing from 1 to 5hydroxyls, lower alkylene, monochloro-lower alkylene, mononitro-loweralkylene, phenyllower alkylene, cyclohexyl-lower alkylene,dichloro-lower alkylene, and hydroxy-lower alkylene, containing up tothree hydroxyls, alkoxyalkyl wherein the alkoxy and alkyl radicals areeach of up to ten carbon atoms, lower alkoxy cycloalkyl, wherein thecycloalkyl is of 5 to 6 carbon atoms, lower alkene, and cycloalkene,wherein the cyclic radical is of 5 to 6 carbon atoms.

4. An ester of phosphonic acid having the formula having from 6 to 54carbon atoms and from 2 to 11 hydroxyls, wherein R is independentlyselected from the group consisting of hydrogen, alkyl of l to 10 carbonatoms, lower alkyl substituted phenyl, phenyl substitutedlower alkyl,nitro, chloromethyl, brornomethyl, iodomethyl, monohalophenyl,dihalophenyl, hydroxy-lower alkyl, containing from 1 to 4 hydroxyls,phenyl, alkoxyalkyl,

wherein the alkoxy and alkyl radicals are each of up to ten carbonatoms, hydroxy-lower alkoxy-lower alkyl, containing from 1 to 5hydroxyls, lower alkene, lower alkyl substituted lower alkene,monohalosubstituted alkene, and Z is selected from the group consistingof lower alkylene, hydroxyl substituted lower alkylene containing up tothree hydroxyls, and monohalosubstituted lower alkylene.

5. An ester of phosphonic acid having the structure 0-011; R"(0H), II/

o-ong R(0H) having from to 54 carbon atoms and from 2 to 11 hydroxylswherein Z is selected from the group consisting of alkyl of 1 to carbonatoms, lower alkene, phenyl substituted lower alkyl, phenyl, lower alkylsubstituted phenyl, monohalophenyl, dihalophenyl, hydroxyl substitutedlower alkyl containing from 1 to 4 hydroxyls, substituted lower alkylcontaining up to two hydroXyls and one nitro, monohydroxy phenylsubstituted lower alkyl, monohydroxylower alkyl substituted phenyl, andR is selected from the group consisting of hydrogen, lower alkyl of 1 to10 carbon atoms, lower alkene, nitro, halomethyl, phenyllower alkyl, andlower alkoxy-lower alkyl and the sum of x and y is an integer greaterthan 1.

6. An ester of phosphonic acid of the formula O-CHz having from 10 to 54carbon atoms and from 5 to 11 hydroxyls, wherein Z is selected from thegroup consisting of alkyl of 1 to 18 carbon atoms, lower alkene, phenylsubstituted lower alkyl, phenyl, lower alkyl substituted phenyl,monohalophenyl, dihalophenyl, hydroxyl substituted lower alkyl, havingfrom 1 to 4 hydroxyls, monohydroxy phenyl, monohydroxy phenyl-loweralkyl, and monohydroxy alkyl phenyl, and X is a halogen selected fromthe group consisting of chlorine, bromine and iodine.

7. Pentaerythritol butane phosphonate.

8. Bromodipentaerythritol decane phosphonate. phosphonate.

9. Chlorodipentaerythritol-S-methylene ethyl furfural phosphonate.

10. Chlorodipentaerythritol furfural phosphonate.

11. Bis-chloropentaerythritol xylene diphosphonate.

References Cited UNITED STATES PATENTS 3,152,164 9/1964 Oswald 2609373,209,014 8/ 1965 Hechenbleikner 260937 2,974,158 3/ 1961 Lanham 260927OTHER REFERENCES Van Wazcr: Phosphorus and its Compounds, Volume I,N.Y., Interscience Publishers, Inc., pp. 383-84 (1958).

ALEX MAZEL, Primary Examiner B. I. DENTZ, Assistant Examiner US. Cl.X.R.

P0405) UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3, 51 l 57 Dated M y T 197 Inventor) Charles F Baranauckas et al It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

' Column 3, line l0, delete formula and insert CH Br 0 OCH CH CH u/ 2-CH -P CCH -0CH -C-CH OH O 2 2 2' 2 OCH CH OH Olumn line 5, delete"phospite" and insert phosphite Column l, line 33, delete "7-dishydroxy" and insert 7-bi shydroxy Column 5, last formula under Alkyldelete and insert CH3 l H C- H cH H H Column l0, line 56, delete epibrimohydrin" and insert epibromohydrin Column ll, lines 2 and 6, delete"diepentaerythritol" and insert dipentaerythritol Column ll, line 20,delete "phosphinate" and insert phosbhonate 3 3 UNITED STATES PATENTOFFICE CERTIFICATE OF CORRECTION Patent No. 3 ,5l l,857 Dated y 97Inventor(s) Charles F. Baranauckas et a l It is certified that errorappears in the above-identified patent and that said Letters Patent arehereby corrected as shown below:

Column 12, Formula l, line 7, delete formula and insert CH CI O 0'/CH20\" o-cH CH Cl H001 c /P-CH2- O cH c cH o \0-CH2/ CHZOH Column l7,line I}, delete "diflur-o" and insert difluoro Column l8, line l, delete"pantae and insert pentae- Column 20, line 6, delete formula and insert0 O O-CH cH c1 C H OC-Q -CH -P 2 c Column 21, Example l5, line 6 deleteformula and insert O-CH P,-0-CH -C-CH -0-CH -C(CH 0H) -CH 0-CH -C(CH 0H)mg UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,5l1,857 Dated M y 97 Inventor(s) Charles F. Baranauckas et al It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

Column 22, Example 19, line 55, delete formula and insert 0 0-CH2\ CH BrCHZOH CHZOH CH3-(CH2)9-P\ c I I 0-CH2 EH20CHZE-CHZ-O-CHZ-(E-CHZOH CH OHCH OH Column 23, Example 21 line 7, delete Formula and insert 0 CH2 CHZOCH2 E CH2 0 CH2 C(CH2OH)3 CHZOH Column 23, Example 25, underneathFormula, delete "Alkyl phosphinate". Column 2 Example 26, line 3, deleteformula and insert 0H CHZOH 0 I I O-CH\ N0 2 CH3CH2CH-C-CH2-P/ c 2 I0-cH CH-CHZ-CH N02 2 I 3 T222 3 UNITED STATES PATENT OFFICE CERTIFICATEOF CQRRECTION Patent No. 3, 5 l 57 Dated May 12! Inventor) Charles FBaranauckas et al It is certified that error appears in theabove-identified patent and that said Letters Patent are herebycorrected as shown below:

Column 25, line 2l delete "mixted" and insert mixed Column 27, line 50and El, delete Many modifications" and insert Many other modificationsColumn 27, Claim 1, line 70, delete "alky" and insert alkyl Column 29,Claim 6, line 33, delete "and' and insert or SIGNED AND F Tali.

qsEAL) Atteat:

mm 1:. suaum, m.

Officer Oomissioner of Patent

1. AN ESTER OF PHOSPHONIC ACID, OF THE FORMULA 